A lot of people wonder, why does a really expensive, powerful rocket get stopped by the weather? Well, a number of factors. In the case of the recent SpaceX launch attempt to send people to the International Space Station, the safety of the crew is paramount. The launch vehicle itself has a lot to do with it.
Why was the launch scrubbed today?
You got up extra early in the morning, headed down to Cape Canaveral and staked out your viewing seat, and waited for hours. Regardless if you are waiting for a SpaceX Falcon 9 or ULA Atlas V rocket to lift-off, you feel utter dismay when you hear the dreadful words, this launch just got scrubbed.
To answer that, we need to look at the rocket that was launching. In the case of the SpaceX Crew Dragon Demo-2 mission, inclement weather doused the hopes of millions of people. Why though? Launch commit criteria. ()
Is the SpaceX launch a go?
The Falcon 9, like other rockets, has launch criteria. The rocket is not permitted to launch under any of the following criteria:
- the sustained wind at the 162-foot level of the launch pad exceeds 30 knots.
- upper-level conditions containing wind shear that could lead to control problems for the launch vehicle.
- within 30 minutes after lightning is observed within 10 nautical miles of the launch pad or the flight path, unless specified conditions can be met.
- within 10 nautical miles of an attached thunderstorm anvil cloud, unless temperature and time-associated distance criteria can be met.
- within 10 nautical miles of a detached thunderstorm anvil cloud.
- within 3 nautical miles of a thunderstorm debris cloud, unless specific time associated distance criteria can be met.
- within 5 nautical miles of disturbed weather clouds that extend into freezing temperatures and contain moderate or greater precipitation, unless specific time-associated distance criteria can be met.
These criteria may seem a little excessive, but there is good reason. Risk of loss of crew. One of the worset spaceflight disasters happened because the technical details of the launch vehicle came into a stark contrast of the weather.
The rules put in place for the SpaceX Falcon 9 stem from years of lessons learned. Technical evaluations of each system, each launch vehicle, and the support equipment need to be carefully done. The limitations of the design determine the criteria. Just like you would not want to fly a kite in a thunderstorm, or you would not want to bring your iPhone SCUBA diving down 100 feet, there are limitations to the technology sending people and things into space. NASA unfortunately learned this deadly lesson during the human spaceflight program during a televised broadcast.
The space Shuttle Challenger & the Space Shuttle:
A stark reminder of how weather can impact a rocket launch.
For the space shuttle, NASA also closely monitored weather forecasts provided by the U. S. Air Force Range Weather Operations Facility at Cape Canaveral. For three days prior to the launch, weather trends and the possible effects on launch day constantly get examined.
Several milestones along the way to liftoff need to meet criteria to determine if pre-launch weather conditions remain suitable and safe. Launch weather forecasts, ground operations forecasts, and launch weather briefings for the mission management team and the space shuttle launch director include not just the launch site, but also all emergency landing sites as well as long term forecasts for the end-of-mission landing site. The Space Shuttle in orbit time depends on the shuttles onboard supplies for power, food, air and water. Long term planning remains a critical part of the pre-launch.
♦ L-24 hr. 0 min. – Briefing for flight director and astronauts
♦ L-21 hr. 0 min. – Briefing for removal of rotating service structure
♦ L-9 hr. 0 min. – Briefing for external tank fuel loading
♦ L-4 hr 30 min. – Briefing for space shuttle launch director
♦ L-3 hr. 55 min. – Briefing for astronauts
♦ L-2 hr. 10 min. – Briefing for flight director
♦ L-0 hr. 35 min. – Briefing for launch and return to launch site (RTLS)
♦ L-0 hr. 13 min. – Poll all weather constraints
The launch criteria weather checklist is similar to the Falcon 9 pre-launch criteria. One key item that is included in the Shuttle launch is Temperature.
Space Shuttle Weather Launch Commit Criteria and KSC End of Mission Weather Landing Criteria Feb 5, 2010
“Temperature. Prior to external fuel tank propellant loading, tanking will not begin if: a) The 24-hour average temperature has been below 41 degrees. b) The temperature has fallen below 33 degrees at anytime during the previous 24 hours. After tanking begins, the countdown shall not be continued nor the shuttle launched if: a) The temperature exceeds 99 degrees for more than 30 consecutive minutes. b) The temperature is lower than the prescribed minimum value for longer than 30 minutes unless sun angle, wind, temperature and relative humidity conditions permit recovery. The minimum temperature limit in degrees Fahrenheit is specified by the table below and is a function of the five-minute average of temperature, wind and humidity. The table becomes applicable when the observed temperature reaches 48 degrees.”
The Temperature constraint became a problem during the Challenger launch. The temperature dropped below a level that the Solid Rocket Boosters could support. As a result of the horrific Challenger accident, the temperature commit requirements faced revision as the reality of the o-ring seals on the Solid Rocket Boosters became a deadly limiting issue.
What is CCP? and why?
NASA decided the continued risk and cost of operating the space shuttle exceeded the benefit. NASA shifted from launching crews on the Space Shuttle to using launch services provided by Russia. At first, these launch costs were much cheaper than the US costs. Over time, these costs rose quickly. (Read the full article on Soyuz seat costs)
Commercial Crew Program (CCP) has put in motion to facilitate the development of a United States (U.S.) commercial crew space transportation capability. The ultimate goal of the program is to achieve safe, reliable, and cost effective access to and from low Earth orbit (LEO) including the International Space Station (ISS) which is due to be operational through 2024. NASA has purchased commercial services to meet its ISS crew rotation and emergency return rather than continue to rely on the Russian Soyuz spacecraft which launches from Baikonur Cosmodrome launch site. NASA will now utilize spacecraft developed and launched from US soil.
A primary concern is the safety of the crew. NASA with the new commercial procured spaceflight services from Boeing and SpaceX is seeking to reduce risk to crew and especially reduce the probability of loss of crew (LOC). NASA has established minimum tolerable levels of safety for crew transportation missions to the International Space Station (ISS). The Space Shuttle, as summarized by NASA System Safety Handbook originally had an expected LOC between 1:1,000 and 1:10,000. After re-evaluation from the Challenger and Columbia disasters, the LOC estimates were redone several times and estimates ranged from as 1:35 to 1:200. Having such a high risk for humans on the space shuttle helped drive the need for a new vehicle.
Based on studies of known failures for past missions, NASA established reducing the LOC could be partially achieved by reducing risk to crews during launch. NASA raised the bar on safety, and all future crewed missions by including a “launch abort system” LAS, a capability that the Space Shuttle did not have. With the inclusion of a LAS, NASA was able to achieve more than 80% lower risk based on a NASA Ames study. The achievable risk would be much, much lower than that of the space shuttle.
You mentioned Bill Gates – what about it?
In 2009, Bill Gates revealed a plan to stop hurricanes before they could inflict massive amounts of damage and loss of life. Gates along with 12 others filed a patent for water alternation structure applications and methods. (Read the patent application here)
The concept laid out in the patent takes a stab at the heart of hurricanes strength. A series of pumps would suck cold water from the deep and release on the surface. Since warm waters power hurricanes, by lowering the water temperature, the strength of the hurricane conceivably goes down.
Bill later went to support another concept project being pioneered by Harvard scientists. The concept is that large amounts of dust released in the atmosphere would cause a global sunscreen blocking a portion of the light (and heat) from reaching the Earth. This process would be a controlled ice age type event.
Both plans laid out to control the weather have critics advising against the suggested plans. The concern is the tampering might go awry and cause unforeseen consequences.
Bill Gate isn’t alone though in controlling weather. On a larger scale, further away. Elon Musk suggested to “Nuke Mars” His plan includes to detonate nuclear weapons on Mars therefore drastically changing the planet’s climate. They eve have T-shits.
About The Author
Bill D’Zio
Co-Founder at WestEastSpace.com
Bill founded WestEastSpace.com after returning to China in 2019 to be supportive of his wife’s career. Moving to China meant leaving the US rocket/launch industry behind, as the USA and China don’t see eye to eye on cooperation in space. Bill has an engineering degree and is an experienced leader of international cross-functional teams with experience in evaluating, optimizing and awarding sub-contracts for complex systems. Bill has worked with ASME Components, Instrumentation and Controls (I&C) for use in launch vehicles, satellites, aerospace nuclear, and industrial applications.
Bill provides consulting services for engineering, supply chain, and project management.
