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Some of those launch operator-specific weather criteria include how close rain can be to the pad at launch, wind speed and direction, upper level wind shear limits, and others.<\/p>\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2020\/05\/Challenger-ice-launch-e1590343602788.jpg\")
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Ice on the launchpad after temperatures dropped well below freezing in the hours before Challenger\u2019s STS-51L launch. (Credit: NASA)<\/p>\n
Two of these launch-vehicle specific criteria gave the U.S. the absolute hardest lesson it has had to learn about space flight on 28 January 1986 when the Shuttle Challenger was launched in near-freezing temperatures that were 20\u2109 colder than the lowest certified operational limit of the Solid Rocket Boosters.<\/p>\n
The cold temperatures caused the failure of the primary and secondary O-Ring seals on the aft field joint of Challenger\u2019s right-hand Solid Rocket Booster. The failure method caused a temporary seal to form as O-ring material became jammed in the hole.<\/p>\n
This temporary seal was shattered when Challenger encountered the most-intense upper-level windshear ever for a Shuttle (even through to the end of the program). <\/p>\n
Overriding those two vehicle-specific weather rules resulted in the loss of seven people that January morning.<\/p>\n
Scrubs for upper level winds today are cause for great commentary on social media. But as Challenger reminds us, there are serious consequences to flying a vehicle in conditions it\u2019s not built for.<\/p>\n
In addition to vehicle specific rules, there are also Range safety requirements launch providers don\u2019t get any input on. They are the rules in place to protect space center workers and the viewing public on land, in the air, and at sea.<\/p>\n
They include some obvious things like lightning rules to make sure a lightning strike doesn\u2019t destroy a vehicle\u2019s electronics and make it impossible to destroy if it flies off course.<\/p>\n
But there are less-known rules that come into effect that cause launch teams to have to scrub for lightning even when there is no lightning anywhere near the launch pad.<\/p>\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2020\/05\/first-strike.jpg\")
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The lightning bolt triggered by Apollo 12 reaches the Launch Umbilical Tower at LC-39A. (Credit: NASA)<\/p>\n
This is an example of a Range weather rule that exists from experience.<\/p>\n
It was during Apollo 12 when Pete Conrad, Richard Gordon, and Alan Bean\u2019s Saturn V was struck twice by lightning in the first minute of flight.<\/p>\n
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The strikes resulted in the failure of a number of critical flight systems, including the Apollo Command and Service Module\u2019s fuel cells and all navigation displays for the crew. Mission Control received garbled telemetry and communcation from the rocket and crew.<\/p>\n
Thankfully, the Saturn V\u2019s flight computer, isolated from the Apollo spacecraft, was not affected by the strikes and kept functioning as if nothing had happened.<\/p>\n
Saving the mission was made possible by a single flight controller in Mission Control who remembered from over a year prior a series of strange numbers a team asked for his help in determining where they came from. He eventually traced them to the Signal Conditioning Equipment (SCE) on the Apollo Command and Service Module. <\/p>\n
Inside the Apollo 12 capsule, there was an \u201cSCE\u201d button that had to be pressed to start bringing things back online. The button was completely unknown to the Flight Director and the mission\u2019s Commander, but Al Bean remembered it from a completely different training simulation.<\/p>\n
With telemetry and information restored, the mission continued on to orbit, where a full checkout of the spacecraft resulted in a successful lunar landing mission and return.<\/p>\n
What Apollo 12 revealed was a better understanding of how rockets can trigger lightning even when naturally-occurring lightning is not possible. <\/p>\n<\/p>\n
The strikes resulted in the failure of a number of critical flight systems, including the Apollo Command and Service Module\u2019s fuel cells and all navigation displays for the crew. Mission Control received garbled telemetry and communcation from the rocket and crew.<\/p>\n
Thankfully, the Saturn V\u2019s flight computer, isolated from the Apollo spacecraft, was not affected by the strikes and kept functioning as if nothing had happened.<\/p>\n
Saving the mission was made possible by a single flight controller in Mission Control who remembered from over a year prior a series of strange numbers a team asked for his help in determining where they came from. He eventually traced them to the Signal Conditioning Equipment (SCE) on the Apollo Command and Service Module. <\/p>\n
Inside the Apollo 12 capsule, there was an \u201cSCE\u201d button that had to be pressed to start bringing things back online. The button was completely unknown to the Flight Director and the mission\u2019s Commander, but Al Bean remembered it from a completely different training simulation.<\/p>\n
With telemetry and information restored, the mission continued on to orbit, where a full checkout of the spacecraft resulted in a successful lunar landing mission and return.<\/p>\n
What Apollo 12 revealed was a better understanding of how rockets can trigger lightning even when naturally-occurring lightning is not possible. <\/p>\n<\/p>\n