Space History for April 4: Challenger's anniversary

[CalliArcale]

April 4, 1968, Apollo 6 launched from LC-39 at Kennedy Space Center. Launch vehicle was SA-502, the second operational Saturn V. Payload was Apollo CM 020 with SM 014 and a lunar module test article (LTA-2R, basically just a mass model). This unmanned flight was only a partial success. First-stage ascent was normal, but during second stage, two of the J-2 engines shut down prematurely; the system compensated, burning with the remaining three for an extra minute. The third stage burn was longer than expected. As a result, the orbit was more eccentric and much higher than intended. Additionally, oscillations during this phase exceeded design tolerances. Ground control attempted to reignite the S-IVB as planned for a translunar injection, but it would not restart, so they went to plan B. The CSM separated from the S-IVB and burned its main engine to put itself onto a free return trajectory. However, since the SPS was used to do this instead of the S-IVB, it didn't quite have enough delta-vee left to accelerate the CM to simulated lunar return velocities. For test purposes, they went through the entire firing sequence anyway, omitting only the actual burn. The spacecraft reentered the Earth's atmosphere normally and was retrieved by the USS Okinawa. This was the first flight of the redesigned crew access hatch, and the hatch was in good condition after reentry, thus validating it for the next mission, which would be a crewed flight of the Apollo spacecraft aboard the simpler Saturn 1B rocket. Three out of five primary mission objectives were met, and NASA determined that it would be safe to proceed with Apollo 7.<br /><br />April 4, 1983, Challenger blasted off from the very same pad as Apollo 6, fifteen years earlier. This was OV-099's first flight. She carried a crew of four (including the famous Story Musgrave) to deploy the first satellite in the TDRS constellation, mounted on a solid-fuel IUS (Inertial Upper Stage) to boost it to geosynchronous orbit. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[rocketwatcher2001]

That was the first launch that I ever saw from close enough to feel. I've still got the T-shirt, and ball cap. I also saw the first launch of Discovery <img src="/images/icons/smile.gif" />, and I lived in Virginia at the time, but I have a really cool Dad, who didn't mind taking me out of school for a few days so I could get a real education. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> </div>

 

[bpcooper]

Soyuz TM-30 should be 2000 not 1997. <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[scottb50]

The Ides of April? <br /><br />Must be a very good reason though, maybe holiday slipups maturing. <div class="Discussion_UserSignature"> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Soyuz TM-30 should be 2000 not 1997. <p><hr /></p></p></blockquote><br /><br />Whoops! That's what I get for cut-and-pasting to start the line. *blushes* I've fixed it. (That's not the first time I've done that, either, so I really should know better.)<br /><br />Thank you for the correction. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>The Ides of April? <p><hr /></p></p></blockquote><br /><br />Actually, that would be April 13. The "ides" of a month is its midpoint, which is 15 for the 31-day months, and 13 for the others. (I'm not sure why it's not 15 in the 30-day months, though.) <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>