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REV 2.4 - Tue Aug 17 08:34:52 2010

Estes Industries
Venus Probe
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SPECS: 27" x 1.325" - 5.1 oz
ROCKSIM FILE: Right Click to Download
SpaceCAD FILE: MISSING - please submit here
REC'D MOTORS: C5-3, C6-3

- by Tom Bell 

The Venus Probe is an unusual Estes kit to build and fly. There are two pieces to the completed rocket - a booster and a three-legged lander, complete with an alien on top.

This is NOT an easy rocket to build, and should only be built if you have built several rockets already.

The Venus Probe's instructions, at first glance, seem to be complete and well illustrated. But, when you read them, you find that they are numbered strangely. The assemblies have numbered sections, but these are not consecutive through the entire instructions.  For example, the lander has steps 1,2,3 and so on; the booster has steps 1,2,3 etc. The pages are not numbered, so it is easy to get confused.

Instruction sheets should always have every single step numbered consecutively from beginning to end. Estes does this with most of their kits, so they should know better.

The usual tools were needed, including plastic cement for the lander. Wax paper is needed to lay the fins on while they are drying.

Again, this is not an easy kit to build. The fins come in sections, so they have to be glued together and put on wax paper to dry. This is not as easy as it sounds, as they must be lined up precisely.

The lander stage is also somewhat complicated, as the landing legs must be assembled from many small pieces of dowel and plastic.

An assembly hint: Make sure the alien's back is directly in line with one of the lander legs. The alien's back is where the parachute is attached, and it does not make a three-point landing, the front side of the alien lands first. You want two legs to cushion the blow and stabilize the landing, so make sure there is only one landing leg behind the alien's back.

All the parts were in my kit and alignment was very good.

This kit is a sturdy one. I have never had any problems with the lander or the booster unit, despite several launches and many hard landings. Another reviewer indicated a problem with their body tubing, but the body tubes on my Venus Probe are still in fine condition.

The only possible weak link is the BT-20 body tube which connects the top tube and the bottom tube of the booster. Again, I have had no problems with this. But, you could strengthen this tube by making "cooling fins" that extend the length of the body tube.

Decals are excellent and help improve the look of the model. This model looks great with the recommended black and white paint job, which is easy to do by masking the model.

The only complaint I have in this area is that Estes recommends that the alien be painted fluorescent green. Everybody knows that REAL aliens are gray, so I painted mine accordingly, with gloss black eyes.

My Venus Probe is a veteran of several flights, including some hard landings. The alien has landed on his head, with no other apparent damage than a possible headache. The booster has lawn-darted, collecting a 3" core sample for the alien to bring back to his home planet. But this is a sturdy rocket and has survived all of these Roswell-type landings, without any alien autopsies to date.

Before I built my Venus Probe, I noticed that other people had lackluster performance with their Venus Probes and the recommended Estes C6-3 engine. I do not recommend this engine combination, it barely gets the alien high enough to eject. There are two different ways to solve this problem: One is to use Aerotech 18mm engines, which will give your Probe more power. The other is to re-fit the Probe with a 24mm engine mount and use Estes D12-3 motors in it.  I chose this method, as D12-3's are less expensive than Aerotech D's.

I designed my own "D" motor mount and used the existing body tubes, but if you need plans for a "D" motor Venus Probe, they can be found in the September/October 1997 issue of Sport Rocketry, on page 19. My Venus Probe flies magnificently on "D" motors, powering up to a respectable height and putting on a crowd-pleasing show. I recommend using "D" motors in the Venus Probe.

Recovery is tricky with the Venus Probe. The upper body tube is not very large for two parachutes. I had several chute failures until I figured out the solution: don't use any 18" chutes.  I use a 12" chute for the booster and an 8" chute for the lander.  These are dusted heavily with talcum powder before flight, to prevent sticking.  Since I started using smaller chutes, I have had successful landings.

The Venus Probe would have gotten 5 points from me, except for two problems, the instructions and the underpowered motor mount. It also appears that Estes rates this as a Skill Level 1 kit, which would be an error. This kit is at least a Skill Level 2.

I rate this rocket at 3 ½ points.

I recommend the Venus Probe to anyone who wants an exotic, X-Files kind of rocket. It is a real crowd-pleaser, and fun to build and fly.

(by Doyle Tatum) 

[Picture]First, I would like to say that this is not a skill level one rocket. It has lots of dowel cutting and such and should be a level two. Also, this rocket is dangerously underpowered on a "C" motor (leaving RSO's in a bind at launches - definitely a heads-up model!). I used the instructions from Sport Rocketry magazine to upgrade mine to a 24mm mount. I believe that the rocket is now not only safe, but actually looks better. Following the directions carefully, the model built flawlessly. I added a Kevlar shock k cord line from the motor mount and soaked the fins in CA (one has cracked anyway!). The rocket flies beautifully on a "D" and is spectacular on an "E30" composite. I bring the lander down on an 18" X-Form and the booster on a plastic 18" with spill hole Each landing, both pieces have been in close proximity to each other. I recommend this rocket - with the 24mm upgrade only! NOTE: Last flight, at ejection, the motor hook blew out the rear with the motor?!? I used an engine block, at the top of the motor hook, when constructing - so I'll just friction fit (tape) the motors in from now on. 

(Contributed - by Dave Sutter) 
 This isn't really my rocket... it's my wife's rocket. When I was getting my second rocket, she was curious enough to try a rocket of her own. Only problem was, she didn't want to start with some namby-pamby simple rocket... no, she had to go for the most complex rocket in the store... the Venus Probe. Besides, it says "Skill Level 1" on the outside of the box...

Well, she did a great job with it, despite the fact that it's not simple, and it was her first rocket. Our biggest problems with it have been a lack of knowledge on our part, plus a bit of bad luck. The first day we went to launch it, it was slightly windy, say 5-10mph winds. That's just too much for this heavy (and top-heavy at that), slow-lifting rocket... it weathercocks badly in any wind. In other words, it went straight up to the end of the launch rod, pointed into the wind, and took off about 20degress above horizontal on its first flight. Debbie was disheartened; she immediately assumed that she had screwed up building it (which she most definitely had not, as it turns out).

I convinced her to try it again that day. It went good, though not real high. Without a doubt, this rocket is a joy to watch. Encouraged, she wanted to try it again. We put in a C6-3, and... CATO! Wow! Our first (and so far, only ... knock on wood) Catastrophe At Take-Off. The facts are that there was a small explosion immediately upon ignition, causing the rocket to lift to about 10' AGL (above ground level), and causing the motor casing to go backwards, slamming into the blast deflector (denting it pretty good, and breaking the plastic rod standoff). After hitting the blast deflector, the motor, now flaming, proceeded to propel itself about 100' AGL, with no ejection charge 'pop' at the end. Near as I can guess, the propellant grain was cracked, and the ejection charge blew almost immediately, sending the rocket up, and the engine backwards, and then the propellant took over and launched the engine alone. Regardless of my theory, I wrote it all to Estes, and they responded by sending a 3-pack of C6-3s, a 6-pack of igniters, and a 75-sheet pack of recovery wadding. Very nice. They could have ignored me, but they didn't. They sent a perfectly reasonable set of replacements, I thought. (I specifically told them that I had already replaced the blast deflector and launch rod standoff, so I wasn't expecting a replacement for that.)

Obviously, Deb was upset. Thankfully, the alien lander ejected and landed ok, despite the ELF (extremely low flight) from the CATO. The booster, however, was a bit worse for wear, as it crimped a bit just above the motor mount area, and semi-pranged, mashing the very top of the tube, where the alien lander sits. It was to fly again, however...

The second day of flying the Venus Probe wasn't real encouraging, either. The first flight went ok. Low, but an ok boost. The only problem was that the 18" chute for the Alien Lander didn't open fully until about 15ft AGL... a real heart-stopper, and a kinda hard landing, but the Lander was ok. Wasn't really watching the booster, but it seemed to have had a bit of a hard landing, too... the body was crimped again just above the motor mount area. Oh, well, let's try again. Bad idea. Seems that the body tube had bent enough that the launch lugs didn't line up well, only Debbie didn't seem to notice any major problems when putting it onto the launch rod. Well, the motor lit fine, but the lugs and the rod did the binding thing and the rocket never left the rod. It was interesting to see that the engine exhaust burned through not 1 but 2 stacked Estes blast deflectors. (Since I still had the dented blast deflector from the CATO mentioned above, I'd gotten into the habit of stacking the blast plates, with the dented one on top.) Note that I said "burned through", and I wasn't kidding. It left about a 1/2" diameter hole in each blast plate. Fortunately, the launch pad itself was undamaged. For its part, the Alien Lander part took off for another ELF on the ejection charge, and landed hard, and on its side, but unharmed.

Well, Debbie had had enough of rockets, and "gave" the Venus Probe to me. I've decided to ditch the bent, too-weak booster body with the question launch lug placement. So, I'm currently in the process of building a 3" diameter booster for the Alien Lander. This has the double bonus of being very much more rigid, and allowing the launch lugs to be attached directly to the outside of the body tube, rather than having the top one mounted on a stupid post like the stock version. As a third advantage, I can now use larger launch lugs (I can't believe that the stock rocket weighs over 5 oz, but only has 1/8" launch lugs! Come on.) Also wishing to kill a fourth bird with one stone, I've also opted to make the motor mount completely interchangeable. Currently in the works are a 24mm mount for D and E-sized engines, and my first attempt at clustering... three 18mm motor mounts for a 3-B or 3-C blast. That should solve those low-altitude blues... 

Description: Normal rocket... except that the nose cone is a very cool, very complex alien lander that comes down on its own chute. It's a real attention-getter and a certain crowd pleaser.
Purpose: According to my wife: "I wanted something interesting" and "It looks cool"
Motors: C5-3, C6-3
Max Altitude: I dunno, maybe 300ft... but then, that's not really the point with this one...
Length: 27.0"
Diameter: 1.325"/33.7mm (BT-55) - that is the size of the upper portion of the booster body
0.736"/18.7mm (BT-20) - for the lower body tube portion
Weight: 5.1oz
Recovery: Booster - 12" parachute
Alien Lander - 18" parachute
Nose Cone: The Alien Lander
Payload: The Alien (sort of... he's really attached to the nose cone). There's no "payload section".
Fins: 4, balsa, mounted through-the-wall (TTW); two small squares, two large irregular octagons
Notes: This model is quite heavy for a single C engine, so it weathercocks quite a bit if there's any wind at all. In fact, this model, at Estes claimed weight of 5.1oz, significantly exceeds the maximum liftoff weight of the Estes C6-3 engine (rated at 4.0oz/113g), which is a recommended motor! Launch only in calm conditions.

Also, this model is too heavy for the little 1/8" launch rod. Use larger 3/16" or 1/4" launch lugs and rods. If you've already built yours, just attach the bigger lugs to the other side of the fin and upper lug strut, and use those.

Needs (3) 1x2 sheets of recovery wadding to not scorch the 'chutes.

Skill Level: 3 - At least. Yeah, yeah, I know, Estes states a skill level of 1, but that's simply ludicrous. This rocket requires many, many complex steps, all of which must be done right to have either the rocket or the lander come out right.
Part Number: 2120
Price: 21.99

[Submit your Opinion]

05/03 - "If you want to fly the Venus Probe on C6's buy a 6pack of them on eBay for the price of one and wreck them all day long. If you want to keep one around for a while get a length of 29mm MMT from PML. It fits in the fin-can with no fuss-or-muss, and you can fly on F20-7W EconoJets with no added nose weight." (J.H.)

12/02 - "I am 6 years old, and I launched the Venus Probe several times. The first time we put in the wrong engine ( a B engine). It crashed in the field before the parachute came out. We had some good flights on C engines, but once it landed on a tall light post. The last flight was at my school. It landed on the roof and broke into many pieces. Wow what a flight! Kaboom!" (unknown)

03/02 - "My son and I were launching the Venus Probe on Estes C6-3's. With a slight wind or not, it would always cock over after takeoff. I thought we hadn't built it correctly. Altitude MIGHT be 150'...and it was the longest 3 sec delays I've ever experienced watching this thing plummet to the ground before deploying. Several times the rocket chute would toast, it's shrouds would burn and the rocket would lawn dawn. I always felt that we packed enough wadding...but it happened several times (which was always repairable). The lander came down fine the 6-8 times we launched it. One time it didn't deploy until about 40' AG. Then I spoke we Tim at Apogee, purchased some D10-3's. This morning we launched using the new engines. We packed 4 sheets of wadding and this time packed it down to where the small 18mm BT meets the larger upper tube. Like someone else said, "This thing rocks on a D-load". Straight up...High enough that we couldn't make out the lander when it deployed, it was just a dot...Both sections deployed beautifully...Safe recovery. That's the way this thing needs to fly. Now we give the rocket an "A"." (AK)

"Don't fly it in any wind on a C engine! Mine cocked over into the wind, and hit the pavement of the parking lot just at parachute ejection. The alien lander was destroyed, and the parachute section telescoped about six inches down onto the middle BT-20 tube. I can fix the main rocket, but the alien will not have the elastic springed legs on his lander any more, and just have to rely on the parachute. I just have to figure out what to do with the lander leg retention ring..." (D.F.)

"Shock loading when the lander's legs deploy quickly rips the legs free. As an 11-year-old budding engineer put it: As an 11-year-old budding engineer put it: thicker lander walls and a lighter alien.

Venus Probe is indeed heavy. Don't you wish Estes still made the B15 motor? The whole point of this rocket is landing the alien. Slamming it to a thousand feet behind a D12 or a D21 just to get a good liftoff is a waste of propellant. Of what's available, the C5 is probably the best choice." (A.C.D.)

[Enter Rocket Specific Tip]

04/04 - "Each of these tips can be done separately or together: 1) Build this with a 24mm engine mount. The C11-3 has the same altitude as the C6-3, but the higher thrust prevents weather-cocking. D12-5 really works nice. 2) The upper tube is pretty cramped with two parachutes, wadding, shock cord, plus the alien's head. Instead of using the Estes tri-fold shock-cord mount, anchor the shock cord to a piece of Kevlar cord attached to the upper centering ring. Even better, use the elastic Kevlar shock cord from Mile High Rockets. 3) On the pad, this bird is tall and top-heavy and prone to weather-cocking. A 3/16th launch lug and rod will help get off to a good start. 4) During descent, the alien tends to lean forward in his capule because of the way the parachute is attached. When mounting the alien in the capsule, orient him so that he is facing between two legs with one leg straight behind him. That way the initial landing impact will be spread between two legs, not just one." (B.C. )

[Enter Flight Log]
Date Name Motor Ejection/
Wind Notes
03-15-2004 Jim Beaver Est SU C6-3 Just Past (1-2sec) Calm - Nearly perfect flight. Slow impressive liftoff. Shroud lines burned on booster 'chute. No damage to booster. Alien broke loose from lander on landing. Will reattach with epoxy.
06-06-2009 John Bergsmith Est SU E9-4 Apogee - Perfect Calm - First flight using the E9, AWESOME! Nice slow arrow straight boost, with a perfect ejection and deployment. This is a cool rocket that has never failed.
07-10-2001 Les Bradshaw Est SU C6-5 Very Late 5-10 mph winds - Loaded C6-5 instead of C6-3 by mistake. Rocket landed then ejection charge went off. Fortuantly, minimal damage
10-20-2001 Dean Cooper AT SU D21-4 Very Early Light winds - The Venus Probe ROCKS on a D reload !Not enough recovery wadding caused the boosters' 'chute to strip (booster landed perfectly intact), Alien floated across the street of the local park and landed upright in front of the Bus Stop(Station) ! VERY cool !
05-19-2002 Dean Cooper AT RMS D13-4 Very Early Calm - Great launch as usual on a D, but delay problem caused ejection on the way up! Both booster and Alien suffered no ill-effects!
04-04-2004 Bob Cox Est SU C11-3 Apogee - NC Up 5-10 mph winds - Arrow-straight boost. Clean eject and good deployment of both cutes. Booster landed first. Lander descends much slower, with perfect 3-point landing. PERFECT FLIGHT!
04-04-2004 Bob Cox Est SU D12-5 Apogee - NC Down 5-10 mph winds - Long straight boost. Arced into wind near apogee. Clean deployment of both chutes. Booster landed safely first. Alien descended slowly with some chute coning. One leg dug in a bit on landing. PERFECT FLIGHT!
04-27-2004 Bob Cox Est SU C11-3 Apogee - NC Down 5-10 mph winds Event: Scout Launch
- Slow fiery boost. Gentle arc into wind. Alien lander ejected clean; good chute deployment and safe landing. Booster section burned through all shroud lines, tumbled to hard landing on one fin. Kinked connecting tube; probably fixable.
05-22-2004 Bob Cox Est SU D12-5 Apogee - NC Down 0-5 mph winds - Loud straight boost. Ejection just past apogee. Booster: Wadding tangled in shroud lines; chute twirled a lot during descent. Lander: One leg bracket broke loose at ejection. Landed safe on other two legs. Easily fixable.
11-13-2004 Bob Cox Est SU D12-5 Just Past (1-2sec) 0-5 mph winds - Arrow-straight boost, then arced over and ejected. Booster chute (15 Rockethead mylar) opened right away. Lander chute (18 Estes) took several seconds to open. Both descended nicely. Lander ended 20 ft from pad; booster landed 40 ft away.
06-12-2005 Bob Cox Est SU C11-3 Apogee - NC Up 0-5 mph winds - Fast straight boost, good coast, ejection. Alien lander chute opened immediately. Booster chute got tangled in fin without opening. Booster came in HARD, nose first, telescoped upper body clear down to the fins. OUCH! Alien made perfect 3-point landing.
05-21-2006 Bob Cox Est SU C11-3 Apogee - Perfect 0-5 mph winds - Fast boost, long coast, then appeared to hang in midair. Perfect horizontal ejection. Soft landing for booster. Perfect 3-point landing for alien. Very nice!
10-28-2000 David Fergus Est SU C5-3 Apogee - NC Up 0-5 mph winds - FLEW GREAT WITH NEW NOSE SECTION USING THE OOP - ESTES SPACE FIGHTER COCKPIT. Now it looks like a real deep space probe.
04-15-1999 David Fergus Est SU C6-5 Very Late 10+ mph winds RIP - Severe wind cock into wind, had set up next to a parking lot with the field downwind; MISTAKE; ejection seconds before impact driving lander into pavement even faster; lander totally destroyed, not fixable. Status: Not Repairable
11-07-2000 Alex Immerman Est SU C5-3 Just Past (1-2sec) Light winds - Slow arching boost, a little under-powered. Only went a couple hundred ft. Next time I would use an Aerotech D21 instead. Recovery was successfull but a little too close for confort. Note: date is approximation.
04-24-2002 Jeff Karnacki Est SU C6-5 None - Nose Cone Stuck Calm - It is a very under-powered rocket with a C engine. The first time I flew it I used a C6-5 engine and was about 2 ft. of the ground before the alien ejected. It crashed! It only went about 100ft. as supposed to 300ft!
04-24-2002 Jeff Karnacki Est SU C6-5 None - Nose Cone Stuck Calm - It is a very under-powered rocket with a C engine. The first time I flew it I used a C6-5 engine and was about 2 ft. of the ground before the alien ejected. It crashed! It only went about 100ft. as supposed to 300ft!
03-03-2002 Allen Kezer Apo SU D10-3 Apogee - NC Down Light winds - The rocket was meant to fly on a D-load. C's just don't get it up. D10-3, perfectly straight flight, perfect deployment, perfect landing.
06-01-2007 Mark Van+Luvender Est SU D12-5 Just Past (1-2sec) 5-10 mph winds RIPEvent: NSL 2007
- Great flight, a little late on the ejection, but not bad. Broke two mounts for the legs on ejection, so it's pretty much dead. Status: Not Repairable
10-14-2000 Larry Zeilmann Est SU C6-3 Apogee - NC Up Didn't Record - good flight
11-03-2000 Larry Zeilmann Est SU C6-3 None - Parachute Fail Didn't Record - slight Damage due to motor block failure, repaired
04-01-2001 Larry Zeilmann Est SU C6-3 Apogee - Perfect Light winds - Great flight
05-06-2001 Larry Zeilmann Est SU C6-3 Very Late Gusty - Rocket vained near horizontal in strong gusty winds. Chute opened ten feet of ground. no damage.
06-16-2001 Larry Zeilmann Est SU C6-3 Very Late 5-10 mph winds - late deployment but good recovery
07-14-2001 Larry Zeilmann Est SU C6-3 Apogee - Perfect 0-5 mph winds - Great flight
08-11-2001 Larry Zeilmann Est SU C6-3 Apogee - NC Down 0-5 mph winds - Another weak but satisfactory performance.
10-13-2001 Larry Zeilmann Est SU C6-3 Just Past (1-2sec) 10+ mph winds - AGF
11-10-2001 Larry Zeilmann Est SU C6-3 Just Past (1-2sec) 0-5 mph winds - AGF
04-23-2002 Larry Zeilmann Est SU C5-3 Apogee - Perfect 5-10 mph winds - AGF
06-01-2002 Larry Zeilmann AT RMS D13-4 None - Unknown 10+ mph winds - Lawn dart, scheduled for Sick Bay repair.
06-01-2002 Larry Zeilmann AT RMS D13-4 None - Unknown 5-10 mph winds RIP - long dart Status: Lawn Dart

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