Science junior overheating on reentry

[Klapaucius]

I'm doing my first ever career playthough. I've tried numerous times to get a science junior in orbit and safely landed back on Kerbin, but despite using a heatshield, they overheat and explode.  

Any suggestions, or do I just need to unlock more tech before this is viable?

[Superfluous J]

They are *HARD* to get down without putting them in a service bay. I personally don't bother.

Instead, get your Kerbal out of the pod and right click the Science Jr and take the data. Then get back in your pod and the data will be in the pod. Then you won't care that it explodes.

You'll get an error that you can't reuse it, but you weren't going to anyway. If you bring a scientist, he can reset it and then you can use it over and over, taking the data and storing it in your command pod each time.

Edited September 17, 2019 by 5thHorseman

[Klapaucius]

1 minute ago, 5thHorseman said:

They are *HARD* to get down without putting them in a service bay. I personally don't bother.

Instead, get your Kerbal out of the pod and right click the Science Jr and take the data. Then get back in your pod and the data will be in the pod. Then you won't care that it explodes.

You'll get an error that you can't reuse it, but you weren't going to anyway. If you bring a scientist, he can reset it and then you can use it over and over, taking the data and storing it in your command pod each time.

Thanks for the great advice!

[Snark]

19 minutes ago, Klapaucius said:

I'm doing my first ever career playthough. I've tried numerous times to get a science junior in orbit and safely landed back on Kerbin, but despite using a heatshield, they overheat and explode.  

5thHorseman's advice is what I virtually always do, they're just not worth the bother of bringing back.

It's also worth noting that having them directly attached to the heat shield won't help you, because the heat shield itself gets hot enough to make them go boom just from touching it.  Most KSP parts can handle 2000 K, but the Science Jr. only goes up to 1200 K, and the heat shield itself gets hotter than that, so any part in direct contact with it is likely to get toasty.

Not to mention that if you've got a 1.25m part like the Science Jr. sitting directly atop a 1.25m heat shield, there's no margin for error on orientation-- if you deviate only slightly from perfectly retrograde, even momentarily, the sides of the Science Jr. will get exposed to heat and then kerboom.

As an example of where it's not a problem, consider the case where, for instance, you have a Mk1-2 command pod, with a 2.5m heat shield on the bottom, and the Science Jr. attached to the top  In that case, it has no problem at all:  the 2.5m heat shield and pod make a nice big wide "heat shadow" with plenty of safety margin all around the Science Jr., and also it's not directly touching anything hot.

[bewing]

SciJr's are easy to reenter, if you just take advantage of aerodynamics. When you launch your rocket, you want it to be in a low drag configuration. When it reenters, you want it to be in a high drag configuration. To do that, you need control surfaces, and you need to actually use them. Yes, if you just reenter a SciJr-containing craft ballistically, you won't make it. You have to be smarter than that. Part of the design of the game is to punish you for just thinking inside the box.
 

 

Edited September 17, 2019 by bewing

[VoidSquid]

If you have a bit of fuel left, braking when reentering the atmo helps a lot. And have a shallow reentry angle helps too. Plus reenter from a low circular orbit. Finally, have a light vessel.

Edited September 17, 2019 by VoidSquid

[mk1980]

if you didn't unlock the ability to EVA yet (i think it requires some building upgrades in career?) you can use the "Experiment Storage Unit" part. it has a function to collect all data from all experiments on the vessel. IIRC the storage unit part is unlocked by the same tech that unlocks the science jr. part

it's a 0.625m part so you can (for example) put it between the mk1 capsule and the parachute or put it in a 1.25m service bay below the capsule.

[ThrashNeon]

On 9/16/2019 at 8:51 PM, 5thHorseman said:

They are *HARD* to get down without putting them in a service bay. I personally don't bother.

I'm a brand n00b, so I'm glad I didn't know this, lol..

Guess I got lucky - I had a Jr on my very first Kerbin orbit and didn't have any trouble at all with it. 1.25m Heatshield + 2 drogue chutes + a mk16 made for an easy reentry & splashdown.

[Fraktal]

On 9/17/2019 at 2:59 AM, Snark said:

As an example of where it's not a problem, consider the case where, for instance, you have a Mk1-2 command pod, with a 2.5m heat shield on the bottom, and the Science Jr. attached to the top  In that case, it has no problem at all:  the 2.5m heat shield and pod make a nice big wide "heat shadow" with plenty of safety margin all around the Science Jr., and also it's not directly touching anything hot.

On 9/17/2019 at 12:02 PM, mk1980 said:

it's a 0.625m part so you can (for example) put it between the mk1 capsule and the parachute or put it in a 1.25m service bay below the capsule.

Both of these are very good advice. I always had trouble keeping a science payload launched before I had the 1.25m service bay surviving through reentry, even when I offset it into the capsule as much as aesthetics allowed. But following this advice, I experimented with hanging goo canisters off a girder between the top of a Mk1 capsule and a parachute and it was perfect, with the canisters never even showing the overheat bar. For an added bonus, it also made the final stage's silhouette resemble that of a Mercury capsule. 

While this tower configuration adds some stabilization as well, it's sadly still not enough to make a KV-1 usable beyond a short atmospheric hop.

[pincushionman]

If you have Making History, you can use the Gemini-style 1.875m capsule with a matching short tube underneath. Stuff a Science Jr. on the inside (the tube is hollow and you can still access the node on the bottom of the capsule). Put a 1.875m heat shield on to the bottom of the tube so the SJ is still isolated from the heat.

This setup is juuust too heavy for a single starter ‘chute to slow the craft below the safe impact speed of the heat shield, but that’s okay because when the shield pops it bleeds off the rest of the energy and you end up on the rim of the tube, the rest of the ship intact.