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Experimental USAF space plane breaks record for orbital spaceflight

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Re: Experimental USAF space plane breaks record for orbital spaceflight

#71

Post by DuskStar »

jonathankoren wrote: post #26
egdod wrote: post #23

Earlier quoted context omitted.

I have so far resisted mechjeb (and other mods). Should I give it a try?

Yes. Some mods like kerbal engineer and machine everywhere makes thing less annoying, not easier. It’s the engines, fuel tanks, and science payloads that can break the balance. As for mechjeb in particular, I never found it all that useful except when calculating rendezvous. I could do it myself, but I don’t want to bother with a protractor and calculator.

Mechjeb is also invaluable when doing preprogrammed burns on remote probes with a high light lag like you'll see in Realism Overhaul.

Timing a 30s burn when the probe takes 15m to get the signal is rather irritating.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#72

Post by nwallin »

Phlarp wrote: post #59
gvb wrote: post #32

Earlier quoted context omitted.

The U.S. Air Force's former top civilian, Heather Wilson, said it dips into the atmosphere and uses its aerodynamic surfaces to change its orbit. Ref: https://www.military.com/daily-news/2019/07/23/former-secaf-...

It uses an oblong orbit to gain a small window where the next orbit cannot be perfectly predicted by an adversary that can only watch half the sky. You can't gain delta-v by inducing additional drag on the craft.

If a spacecraft is traveling at 4,000 m/s and it plows headlong into a planet, it has gained 4,000 m/s of delta v.

Delta v a measurement of a vector, not a scalar. The fact that its kinetic energy with respect to Earth is decreasing does not mean it isn't gaining delta v. In addition to the obvious (lowering your apogee) you can also use this delta v to change your inclination. It's not "free" of course- you need to do other engine burns to both put the craft into the atmosphere and then another burn to reestablish orbit once you're out the other side. But it isn't clear to me that this is less efficient than just doing the burns without the atmospheric assists.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#73

Post by [deleted] »

Phlarp wrote: post #59
gvb wrote: post #32

Earlier quoted context omitted.

The U.S. Air Force's former top civilian, Heather Wilson, said it dips into the atmosphere and uses its aerodynamic surfaces to change its orbit. Ref: https://www.military.com/daily-news/2019/07/23/former-secaf-...

It uses an oblong orbit to gain a small window where the next orbit cannot be perfectly predicted by an adversary that can only watch half the sky. You can't gain delta-v by inducing additional drag on the craft.

[deleted]

Re: Experimental USAF space plane breaks record for orbital spaceflight

#74

Post by dmix »

JumpCrisscross wrote: post #46
nradov wrote: post #38

Earlier quoted context omitted.

There's no free lunch in orbit. If it dips into the atmosphere enough for control surfaces to bite then it has to boost back up again to avoid orbital decay. Either way it can't possibly carry enough fuel to do much of that.

> it has to boost back up again to avoid orbital decay It doesn’t have to return to orbit. Switching from an orbital trajectory to a parabolic intercept path would be feasible, and open valuable tactical space.

As long as it can travel back to a US-friendly airfield. Which is probably a large number around the world although few which would support classified vehicles?

Re: Experimental USAF space plane breaks record for orbital spaceflight

#75

Post by salex89 »

wil421 wrote: post #5
forgotmysn wrote: post #3

Earlier quoted context omitted.

to rescue what exactly?

Chinese or Russian satellite “rescuer”.

Well, the Russians are also doing some shady stuff... They call it the Sputnik Inspektor.

https://space.skyrocket.de/doc_sdat/kosmos-2519.htm

Re: Experimental USAF space plane breaks record for orbital spaceflight

#76

Post by dmix »

gdy wrote: post #69
colechristensen wrote: post #16

Obvious missions for a long-mission mobile shuttle like this include * intercepting and deorbiting space junk * fixing friendly or sabotaging unfriendly operational satellites * future weapons platform for offense or defense (say intercepting ground-launched sat-killing missiles) * on-demand surveillance (with ordinary spy satellites you have to wait until your orbit is in the right spot, adversaries will know when y…

Sounds like the US started weaponizing space long before it began accusing China and Russia of doing the same.

A hypersonic missile is far more concerning than this. If we're talking about offensive capabilities...

Besides that's hardly a surprising statement. Of course they are. And Space Force isn't the start of some new space warfare agenda. It's just formalizing and likely just going to add administrative distractions for existing well-funded and productive engineering teams.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#77

Post by batbomb »

nwallin wrote: post #70
Herodotus38 wrote: post #61

Earlier quoted context omitted.

Too late to edit my comment but amateur astronomer was a poor label for the guy who took the picture. He is the best astrophotographer for satellites that I've seen. Here is his personal website where he has his collection: http://www.ralfvandebergh-astrophotography.simpsite.nl/home

There are two groups of people who take pictures of satellites: 1. Amateur astronomers like this guy. 2. Nation states who take clandestine photos of other nation's spy satellites. These pictures are better, but you haven't seen them. For everything else, there's some guy working in the lab who's like, "oh, you want a picture of our satellite? Of course, there's like 40 of them on our press site. Do you need more? I…

(3) Astronomers - usually not on purpose

Re: Experimental USAF space plane breaks record for orbital spaceflight

#78

Post by m4rtink »

tech_yogi wrote: post #45
Tuxer wrote: post #19

Earlier quoted context omitted.

Space isn't like a highway where you can move from A to B at minimal expense. Switching orbits, both orbit heights but mainly orbit inclinations, comes at a very high delta-V expense and therefore propellant expense, which this craft simply doesn't have the volume to hold. This cannot shuttle between LEO stations and switch orbits to imitate multiple observation sats unless those sats and stations are very close in t…

Could it "scoop" matter out of the atmosphere that could be accelerated by solar or nuclear powered ion drive to use as propellant? Alternatively, thinking about the Earth's magnetic field, what if it had a big current loop that could be activated to generate a force and change orbit. I realize that the magnitude of these effects are probably too small to be significant, but could you in principle use them to repeate…

Unlikely it can scoop material and use it for propulsion just yet, though I have seen some articles about ion engines accelerating the rarified upper atmosphere being studied.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#79

Post by riffraff »

thorum wrote: post #41

I'm mainly surprised that we have reusable space planes at all. You'd think that would get more attention.

this still gets launched with a rocket, it's basically a very small unmanned space shuttle, so it's not as "cool" as, say, something that goes to orbit from the ground on its own.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#80

Post by ggm »

jandrese wrote: post #36
clarkrinker wrote: post #15

Anyone with links to credible speculation on the x-37’s mission?

https://www.military.com/daily-news/2019/07/23/former-secaf-... Long term heat management hardware for space electronics. Among other things no doubt.

"I think it creates more misconceptions about what the mission of the X-37B is and could lead to more international concerns that it's some type of weapons platform," Weeden said. "I think that works against U.S. interests because it will create more diplomatic problems for the U.S. when it tries to point out Russian and Chinese 'unusual behavior in space' and push for discussions on space norms of behavior."

In short, "it gives Russia and China one more talking point about how the U.S. is the one 'weaponizing' space, even if that's not true," he said.

That's a huge potential downside. Like the Soviets believing in US first strike intent. Having this craft do odd things only reinforces belief the US is not operating in good faith at all times. And this, when manned spaceflight to the iss depends on international cooperation still.

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