The Explosion
The Routine Request
Day 3 - April 13, 1970. All systems normal. The crew had just finished a live TV broadcast and was settling in for a routine evening. Then Mission Control asked Jack Swigert for a standard bit of housekeeping: "We'd like you to stir up your cryo tanks."
Remember those oxygen tanks in the Service Module from your tour? Oxygen is stored as supercold liquid (-297°F). Fans stir the tanks to prevent stratification and get accurate readings. This had been done dozens of times on previous missions. It should take seconds...
GET 55:54:53 - BANG
Swigert flips the switch...
- 💥 LOUD BANG - Spacecraft shakes violently
- 🚨 Master alarm sounds
- ⚠️ Warning lights everywhere
- 😨 Crew feels the ship lurch
Jack Swigert: "Okay, Houston, we've had a problem here"
Houston: "Say again please"
Jim Lovell: "Houston, we've had a problem"
What They Saw
Through the window:
- "Sparklies" - a glittering debris field surrounding the spacecraft
- Venting gas creating a cloud around them
- Something is catastrophically wrong
- Oxygen pouring into space
On the instruments:
- Oxygen tank 2 pressure: ZERO
- Oxygen tank 1 pressure: FALLING
- Fuel cells: Two offline
- Main bus B voltage: Dropping
- Warning lights: Cascading failures
Lovell: "We are venting something out into space"
The Damage (Unknown Until Later)
What actually happened:
- ❌ Oxygen tank #2 exploded in Service Module
- ❌ Entire 13-foot panel blown off spacecraft
- ❌ Oxygen tank #1 damaged (now leaking)
- ❌ Fuel cells failing (need oxygen to generate power)
- ❌ Service module crippled
- ❌ Main engine (SPS) unsafe to use
The crew won't see the full damage until Service Module jettison at GET 138:02
The Crisis Unfolds
Immediate problems:
Mission Control Realizes:
❌ Moon landing: IMPOSSIBLE
❌ Normal return: IMPOSSIBLE
❓ Crew survival: UNCERTAIN
"Okay, let's everybody keep cool. Let's solve the problem, but let's not make it any worse by guessing." — Gene Kranz, Flight Director
What's At Stake
The math is brutal:
3 astronauts
200,000 miles from Earth
Crippled spacecraft
Limited oxygen, power, water
Nearly 4 days to get home
Margin for error: ZERO
This is now a survival mission.