Did a US Spaceflight ever Launch Retrograde?

[Spike Spiegel]

I know that normally we launch things prograde for several reasons, but I'm wondering if any US mission ever launched retrograde. Does anybody know?

 

[Urwumpe]

I know that normally we launch things prograde for several reasons, but I'm wondering if any US mission ever launched retrograde. Does anybody know?

Vandenberg launches are always retrograde.

 

[Spike Spiegel]

Vandenberg launches are always retrograde.

Ah thanks. That makes perfect sense, given its location.

 

[kwan3217]

Vandenberg launches are typically into high-inclination (near-polar) orbits. A 98deg sun-sync orbit is technically retrograde.

Missile tests from Vandenberg are definitely retrograde, but suborbital.

Explorer 38 RAE-A was launched into a 120deg orbit, but no obvious sign why. It was pretty high, too, ~5200km alt, so maybe it is still sun-sync.

The first few in the OV-1 series were piggybacked on ICBM tests, apparently mounted in a side-mount pod with an apogee kick motor on an otherwise suborbital flight. They went retrograde because that's where their ride was going. OV1-4 and OV1-5 are still up.

This OV1 thing might even make an interesting addon...

 

[Fabri91]

[ame="http://en.wikipedia.org/wiki/Artificial_satellites_in_retrograde_orbit"]http://en.wikipedia.org/wiki/Artificial_satellites_in_retrograde_orbit[/ame] This might be the answer you were looking for!

 

[N_Molson]

Yep. For exemple Israël has no choice : any launch towards east could trigger a nuclear war.

We were talking about orbital debris some time ago, just imagine what could give a collision between a prograde & a retrograde satellite. That would make something like 13.000 m/s !!! Ouch !!

Here's an all-new one :

http://www.spaceflightnow.com/news/n1006/22ofeq9/

But yeah, of course, if you can choose and have a very interesting launch site like Cape Canaveral, there's no real reason to send satellites in retrograde orbit, so it seems logical that Vandenberg mostly launch suborbital tests.

 

[tori]

In LEO you can get close to 22 km/s if your luck is bad enough - that's when two spacecraft in highly elliptical orbits with 180° RInc meet at their common perigee at around 300 km ASL. At that speed an 80 kg dude would be worth about 1100 kg TNT :hmm:

---------- Post added at 08:33 PM ---------- Previous post was at 08:28 PM ----------

One more reason why retrograde is not done that often is increased friction - even the upper atmosphere is rotating, so the 'airspeed' of a LEO satellite is much higher (around +1 km/s), and so is its friction. Reentering into a retrograde-spinning atmosphere is also unnecessarily riskier than entering prograde.

 

[sputnik]

No manned mission, however, has ever launched retrograde. Or even polar.

 

[Fabri91]

Which brings me to the question: which has been the manned mission with highest inclination? SRTM at 57°?

 

[tori]

Even the first one ever went higher than that (Vostok 1, 64.95°).

 

[Kyle]

Vostok 3-5 featured 65 degree inclination orbits.
STS-36 with Atlantis featured a 62 degree inclination orbit. (highest achieved by America)
Highest inclination space station was Skylab too.

 

[Andy44]

Vandenberg launches are always retrograde.

Not always; IIRC Vandenberg can support launches to the southeast along the Baja coast.

 

[tblaxland]

Sources I can find list Vandenberg's available launch azimuths from 147° to 201° (281° for suborbital). The range varies by a few degrees depending on the source (one lists as much as 140° to 315°).

Sources:
http://spaceflight.nasa.gov/shuttle/reference/shutref/sts/launch.html
http://www.satobs.org/faq/Chapter-09.txt
http://www.fas.org/spp/military/facility/00feb_vafb_1.pdf

 

[Urwumpe]

Sources I can find list Vandenberg's available launch azimuths from 147° to 201° (281° for suborbital). The range varies by a few degrees depending on the source (one lists as much as 140° to 315°).

I have 150° to 200° in a source. I think 160° or so is already the launch azimuth for 90° inclination.