Savage: Life boats depend entirely upon the nature of their drives to determine just HOW they can be thrust.
Dan: not likely that turrets will have those kind of facilities... mostly due to drive costs...
Everybody:
If you fail on re-entry, or on skimming, you are thusting sideways into a high-multi-mach (mach 8+) slipstream, from a much reduced flow shockwave. EVEN IF YOU COULD EJECT SAFELY, you're still going to have an exceedingly rough go abaord. I'll conceed that some Traveller designs probably could handle the sudden translation from inside the shockwave to outside... but that's going to be a massive slam upon the passengers... and GComps are limited by TL... so it will be rough EVEN WITH GCompensation.
Skimming, also add the various Mach 5+ current bands you;ll transition through.
For argument's sake, lets assume (for a moment), a gravitic life pod... unlike the thruster based one shown in the JTAS issue, this one CAN land safely...
Now I just sat down (Using MT) and tried to crank out a TL 9 Gravitic Battery Powered Lifeboat. It is doable for 1 hour of gravitics... and 1 person, at 1 ton.
Starship level armor, 40E, puts final mass around 20 tons... TL 9 is 2 MW/H ... Life support and sensors brng another 1 MWH for 25 hours...at TL 10, it drops to a reasonable 0.4MW/H. At TL 12, it trops again to 0.2MW/H... Kock off (TL9: 0.4 KL, TL 10 1KL, TL 12 0.6KL) volume for it.
Now, it's got 1.5 KL of Junk... Mod 0, LS (BEnv, BLS only), half a dozen control panels, etc, and needs roughly 24 hours life time... and this stuff is pretty much TL independant. plus it needs 10 hours gravitics to assure safe landing on any habitable world. (TTB).
So at tl9, we get 12.5 KL for batts and people, needing 21KWH... Nope. Ain't happening, at the measly 0.6 KWH per KL. So, compromise. 2 people, 4 KL. 8.5 kl Bats... 4.1 hours of flight time. Ouch! So, we'll assume a parachute, too. Either size 4 with any atmosphere, or 5 with VThin, 6 with thin, 7 with Std, 8 wiht Dense... roughly SWAG'd... Rough cost is under a million. Just barely.
at TL 10. we get 0.8 KWH per KL for bats, and have 12 KL to split. Needing 5KWH, we can do 6.25 KL of bats,... heck, go with 7 KL... and we now get three people safely down on ANY standard traveller rocky world. (Two cramped, one no access... esentially, this is the guy in the far end...) Rough cost is 1.5 million
At TL 12, batteries go up to 1 KWH/KL. Sooo... with the reduction in size again, we get about 12.5 again. we need 3 MWH for safety, and we'll give plenty of spare: 3.4KL battries, and thus 3.4 KWH... 12 hours thurst. 9KL for people. One with no access space, 4 more with cramped. So we get a 5 man for 1 ton design. Rough cost is 6.5 million... Or, for the more budget minded, 3 cramped and 3 at none... (in short, 3 people need to crawl over other seats, and 3 people have a narrow space to move.)
BTW, for people in non-tailored vacc-suits, Access space for seating in the mercury would be cramped... race cars vary from craamped to none... the TL12 6 man would be essentially limited to 3 in vaccsuits, and 3 not... and no room for the latter to get into them.
The viability of the TL 12 as pert of SR designs is possible; assume 1 per 3 SR, and the cost (and space, 1 Td) disappear into the SR's.
The TL12, at much less space, provide 1 per 4, and you add nearly MCr 1 per SR above the above costs.
Now, as for viability... well, gravitic descents are NOT happy in hostility. If you're out past 100 Diameters, don't count on maneuvering. Past 10, you'll get less than 1/10 G.... but, you simply kick, and wait... then elock when you are about to hit atmosphere.
Now, if you want one-man pods, the TL9, as a one man already, is pretty dicey. The TL 10, replace the extra seats with more batteries and long term LS (but still no sleeping space).
the TL 12 is MUCH better for a 1 man... he's got a day's maneuver, and 2 days LS... plus unused maneuver will be more LS. also, at Tl 10 and 12, you add Inertial Comp. No A/G, needed, but the IC makes the mid-entry eject survivaable (but still not pleasant.
What these will not do:
keep you alive long enough for non-orbital evac to be resuced.
Keep you alive in a GG unless there are orbital craft to come in and snag you right off.
Make it to orbit with any safety margin.
Be comfortable. Think of it like the space aboard one of the mini-subs, like alvyn. Cramped, functonal, and one guy is in spot that requires someone else to get unseated for him to move. No privy. (Use a diaper, dude...) Nowhere to move to if there is no habitable atmosphere outside. Ever driven 800 miles in a subcompact? Now, think about doing it without stretch breaks....
What they will do:
autopilot is likely, and a dumb-bot pilot brain can be added at cost but negligible volume and weight (for our purposes, at least).
It probably will have an entertainment package in the computer... just to keep you occupied.
Call for help.
Let you know if the atmosphere is breathable.
Find you a planet to land on in the orbital environment.
Let ou transfer to a ship or staation also in orbit.
They could be made airframe for little extra cost....
solar panels as an option add considerable expense, and the conditions will drive you batty anyway before you'll drain the batts on minimum ops (0.0275KW draw for LS, Mod 0, and 1 control panel... and the three square meters of optional solar panel will be enough for that...)
Not terribly useful. In most cases, recue balls will be adequate; if you're close enough for
And recue balls are FAR cheaper.