# The Great Ongoing Space Exploration Thread **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Tags:** science-math\ **Created:** [November 16, 2020, 12:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703 "2020-11-16T12:18:17Z")\ **Posts on this page:** 20\ **Page:** 44
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 12:57pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/862 "2023-08-11T12:57:37Z")
Actually it’s a pretty big distinction. They are not in any sort of orbit. A lot of people don’t realize that the large majority of energy required to achieve LEO is the iknitic energy of orbital velocity, not the potential energy of lifting up there. That’s why I say that the Virgin thing (and the Blue origin one) are really nothing to do with real space travel, just a brief vertical hop off the surface. ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [August 11, 2023, 1:37pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/863 "2023-08-11T13:37:14Z")
I’d argue there’s no distinction if you’re an ordinary (but wealthy) Joe with no engineering or physics knowledge. Or am I wrong? Does the freefall from a parabolic trajectory feel different? When looking at the video from the cabin the passengers weren’t exactly floating around much. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 2:04pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/864 "2023-08-11T14:04:37Z")
The zero-g experience of freefall presumably doesn’t feel any different from orbit. But of course it can only be maintained for a short time since you are in fact actually falling. Still, if you want bragging rights of having been “to space”, I’d say the Virgin or Blue Origin thing is distinctly second rate compared with a visit to say the ISS! ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [August 11, 2023, 2:11pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/865 "2023-08-11T14:11:08Z")
Totally. If I were ever to go to space I would want it to require months of training, I want to have a special breakfast, I want numerous people wearing clean white outfits suiting me up, then I want to be driven to a launch tower, get into a lift that brings me high above the horizon, and then more people in white outfits strap me into a seat in a tiny capsule with minuscule windows. And then I want a countdown. _That’s_ going to space! ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [August 11, 2023, 2:50pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/866 "2023-08-11T14:50:54Z")
> [@xtenkfarpl](#): > > The zero-g experience of freefall presumably doesn’t feel any different from orbit. But of course it can only be maintained for a short time since you are in fact actually falling. You’re actually falling when in orbit, too. You’re just going sideways so fast that the ground falls away beneath you as fast as you fall towards it. In terms of the physics, there’s no distinction between a suborbital trajectory and an orbital trajectory. It’s just that in practical terms, you’ll experience some abrupt braking in a suborbital trajectory when your path intersects the surface of the planet. If you replaced earth with a black hole of the same mass when Virgin Galactic is “in space”, then assuming it has a bit of sideways velocity it would end up in a highly eccentric orbit around that black hole rather than falling into it. How much sideways velocity depends on how big the event horizon of an earth-mass black hole is, but I would expect it to be pretty tiny. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 4:01pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/867 "2023-08-11T16:01:30Z")
> [@Fiendish\_Astronaut](#): > > _That’s_ going to space! And of course the ticker-tape parade on return. Though they don’t seem to be doing those so much nowadays… ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 4:07pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/868 "2023-08-11T16:07:32Z")
> [@Gorsnak](#): > > In terms of the physics, there’s no distinction between a suborbital trajectory and an orbital trajectory. It’s just that in practical terms, you’ll experience some abrupt braking in a suborbital trajectory when your path intersects the surface of the planet. AKA a Rapid Unscheduled Dissassembly. As the saying goes, In theory there is no difference between theory and practice. In practice, however… ---
**Author:** ![Frodo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frodo/32/302_2.png) [@Frodo](https://boards.straightdope.com/u/Frodo)\ **Post date:** [August 11, 2023, 4:13pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/869 "2023-08-11T16:13:56Z")
> [@xtenkfarpl](#): > > AKA a Rapid Unscheduled Dissassembly. Lithobraking is the method, RUD is the result. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 4:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/870 "2023-08-11T16:18:18Z")
> [@Frodo](#): > > Lithobraking is the method, RUD is the result. I like it. So much easier and predictable than aerobraking with all those complicated calculations. We just need a stasis field (as in Ringworld)… ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [August 11, 2023, 4:32pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/871 "2023-08-11T16:32:11Z")
> [@xtenkfarpl](#): > > AKA a Rapid Unscheduled Dissassembly I think that’s the term they use during the launch phase. If it happens during the landing phase, it’s called lithobraking. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [August 11, 2023, 4:50pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/872 "2023-08-11T16:50:38Z")
RUD is any time the vessel explodes when it’s not intended to. Lithobraking is any time you collide with the surface of a planet or other hunk of rock. It’s possible for RUD to be the outcome of a lithobraking event. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 11, 2023, 5:51pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/873 "2023-08-11T17:51:47Z")
> [@xtenkfarpl](#): > > I like it. So much easier and predictable than aerobraking with all those complicated calculations. > We just need a stasis field (as in Ringworld)… Hmm, now I wonder. What happens to the kinetic energy and momentum of the matter inside the _Lying Bastard_,when the stasis field triggers and it hits the ringworld? Next thing we know they are stationary (for Ringworld values of stationary) on the inner surface. This should probably move to a different conversation about dubious ideas in supposely ‘hard’ science fiction? Like spindizzies… I always wanted a space drive that would work off a couple of batteries… 😉 ---
**Author:** ![Icerigger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icerigger/32/432_2.png) [@Icerigger](https://boards.straightdope.com/u/Icerigger)\ **Post date:** [August 11, 2023, 11:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/874 "2023-08-11T23:45:31Z")
I don’t know how I missed this but Voyager 2 is in serious trouble from an errant command sent to the spacecraft. > **[How NASA Nearly Lost the Voyager 2 Spacecraft Forever](https://www.wired.com/story/how-nasa-nearly-lost-the-voyager-2-spacecraft-forever/)** > > The space agency lost touch with the beloved spacecraft following a faulty command signal. Here’s how it happened—and how engineers worked to bring it back. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 11, 2023, 11:53pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/875 "2023-08-11T23:53:23Z")
> [@Icerigger](#): > > I don’t know how I missed this but Voyager 2 is in serious trouble from an errant command sent to the spacecraft _Was_ in trouble, not _is_. But the title is a bit clickbaity anyway. They had at least two backup options: use the radio signal blast, or wait until the automatic system kicked in in October. The first one worked, so there was no problem. I wonder what direction that 2 degrees was, also. If it was in the same plane as Earth’s orbit, it’s possible that waiting for a more favorable time of the year could have improved the radio blast efficiency. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 12, 2023, 6:14pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/876 "2023-08-12T18:14:33Z")
Apparently the Voyagers use magnetic tape for data storage. I’m inpressed that this is still working after all this time! Of course, there won’t be any dust or oxidation in that environment, but to design a system with moving parts that lasts that long is quite an achievement. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 12, 2023, 8:09pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/877 "2023-08-12T20:09:04Z")
Lubrication in a vacuum is very challenging. Liquid-solvent lubes or greases evaporate like crazy and solid graphite-like lubes don’t do much better long term. I wonder if the moving parts of the tape drive are in a sealed nitrogen-filled tank. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [August 18, 2023, 5:11pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/878 "2023-08-18T17:11:53Z")
> **[The ancient technology keeping space missions alive](https://www.bbc.com/future/article/20230815-the-ancient-tech-keeping-space-missions-alive)** > > Some of the most famous space missions have been running for decades. The technology helping to keep them aloft is anything but space age. You wonder how long recent space missions will last. ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [August 18, 2023, 6:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/879 "2023-08-18T18:18:03Z")
Thanks that was an interesting read. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [August 18, 2023, 9:30pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/880 "2023-08-18T21:30:21Z")
A nuclear-powered U.S. Army base on the Moon, 1965. Utterly bonkers. > **[Project Horizon: Army Base on the Moon | Defense Media Network](https://www.defensemedianetwork.com/stories/an-army-base-on-the-moon/)** > > Project Horizon was a Cold War proposal to build an Army base on the moon. > **[SMDC History: Project Horizon: ABMA explores a lunar outpost](https://www.army.mil/article/189129/smdc_history_project_horizon_abma_explores_a_lunar_outpost)** > **[Project Horizon](https://en.wikipedia.org/wiki/Project_Horizon)** > > Project Horizon was a 1959 study to determine the feasibility of constructing a scientific / military base on the Moon, at a time when the U.S. Department of the Army, Department of the Navy, and Department of the Air Force had total responsibility for U.S. space program plans. On June 8, 1959, a group at the Army Ballistic Missile Agency (ABMA) produced for the Army a report titled Project Horizon, A U.S. Army Study for the Establishment of a Lunar Military Outpost. The project proposal states t... ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [August 19, 2023, 10:06pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/881 "2023-08-19T22:06:38Z")
It doesn’t look good for Russia’s lunar lander which is supposed to touch down on Monday. Though details are thin. > **[Russia's Luna-25 spacecraft suffers technical glitch, space agency says](https://www.reuters.com/technology/space/russias-luna-25-spacecraft-produces-first-results-space-agency-says-2023-08-19/?taid=64e137e5f243fd0001dd0b47)** > > An "abnormal situation" occurred at Russia's Luna-25 spacecraft on Saturday as it was preparing to transfer to its pre-landing orbit, Russia's national space agency Roskosmos said. India’s lunar lander Chandrayaan-3 however is still on target to touch down on Wednesday and just took these images of two of the Apollo landing sites!: [![](https://pbs.twimg.com/media/F36Ik0UWMAApxFL?format=png) ](https://pbs.twimg.com/media/F36Ik0UWMAApxFL?format=png) [![](https://pbs.twimg.com/media/F36Ik0WWAAAnuQt?format=png) ](https://pbs.twimg.com/media/F36Ik0WWAAAnuQt?format=png) [Previous page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=43) [Next page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=45)