We booked new awards of $8.9 billion, grew sales 6% and increased segment operating income, 13%.
GAAP earnings per share of $13.43 reflects the IT services gain and transaction-adjusted earnings per share increased 28% in the quarter.
First-quarter operating cash improved by more than $900 million year over year.
Using cash on the balance sheet and divestiture proceeds, we executed a $2 billion accelerated share repurchase agreement that retired an initial 5.9 million shares.
We also retired $2.2 billion in debt, including early redemptions of $1.5 billion.
Even with share repurchases, dividends and deleveraging, all of which totaled more than $4.4 billion, we exceeded the first -- we ended the first quarter with $3.5 billion of cash on the balance sheet.
As I outlined in January, this year's capital deployment plans continue to include robust investment to drive innovation and affordability and at least $1 billion of additional share repurchases.
We now expect sales will increase to between $35.3 billion and $35.7 billion, a $200 million increase to the prior range.
And we are raising transaction-adjusted earnings per share guidance by $0.85 to a range of $24 to $24.50.
Our space business doubled its backlog in 2020 and achieved 30% revenue growth in each of the last two quarters.
On HBTSS, we received $155 million award to build a prototype sensor satellite capability capable of tracking hypersonic weapons from space.
We also were awarded a $2.6 billion contract for the next phase of the Missile Defense Agency's next-generation interceptor, known as NGI, with a period of performance through 2026.
NASA's fiscal year 2022 discretionary requests is $24.7 billion, a 6.3% increase over the 2021 enacted level.
And in commercial space, MEV-1 continues to provide life extension services to an Intelsat satellite and have received via Satellite Technology of the Year award.
I'm also pleased to report that earlier this month, MEV-2 successfully docked with another Intelsat satellite.
MEV-2 will provide five years of service before undocking and moving on to provide services for a new mission.
The B-21 bomber and the Ground Based Strategic Deterrent, or GBSD, as well as a key supplier on the third leg.
Both GBSD and B-21 are benefiting from our use of innovative digital tools to reduce technical risk and cost.
As the Air Force has noted, B-21 development has been unique and that the test aircraft are more mature than other systems have been at this point, allowing us to validate our production processes much sooner in the program life cycle.
In the first quarter, we received orders totaling approximately $500 million for additional SABR radar systems for the F-16.
With these additional orders, we're now under contract to produce approximately 900 systems in the support of F-16 upgrades and new jet procurements for eight FMS countries, as well as upgrades to our US Air Force, Guard and Reserve F-16 fleets.
Also on the F-16 for the US Air Force, we were down selected as the sole offer for the EMD in production of a modern electronic warfare fleet to provide next-generation self-protection and ensure an upgrade path for advanced capabilities against highly agile future threats.
Our fifth-generation connectivity solutions will be featured on multiple platforms in the upcoming Northern Edge 21 Exercise in May.
We expect to participate in several other exercises over the next 12 months, including the Army's Project Convergence, where IBCS is expected to be featured.
We reported Q1 sales growth of approximately 6%.
And as you can see, the IT services divestiture was an approximately $400 million headwind to first-quarter sales.
The three additional days in Q1 2021 result in an approximately 5% benefit to sales across all of our segments for your modeling purposes.
Adjusting for these two items, revenue growth was 6.4%.
GAAP earnings per share increased to $13.43, primarily due to the gain on sale.
When we adjust for the divestiture-related items, transaction adjusted earnings per share are up 28% to $6.57.
The increase reflects strong segment performance, which drove $0.75 of the year-over-year improvement.
Corporate unallocated expense contributed $0.27, primarily due to lower state tax and lower amortization expense in the period.
Aeronautics systems sales were up 5% for the quarter, reflecting higher Manned Aircraft sales due to stronger volume on restricted programs and E-2D, partially offset by lower sales in autonomous systems as certain Global Hawk production programs near completion.
At defense systems, first-quarter sales decreased 17% or 2% on an organic basis.
Lower organic sales reflect the closeout of our Lake City activities, which represented a headwind of roughly $140 million this quarter.
Turning to mission systems, we saw a third consecutive quarter of double-digit sales growth, with revenues up 10 or 15% on an organic basis.
Space systems continues to be our fastest-growing segment, with sales up 29% in the quarter, or 32% on an organic basis.
Sales were higher in both business areas, with continued ramp-up on the GBSD program, driving revenue growth in launch and strategic missiles.
Segment operating income includes a Q1 benefit of approximately $100 million from lower overhead rates, a reflection of our disciplined approach to cost and affordability.
At AS, operating income increased 17% and margin rate increased to 10.3% due to higher net favorable EAC adjustments driven by reduced overhead rates.
Defense systems operating income decreased 11%, primarily due to the IT services divestiture, and operating margin rate increased 80 basis points to 11.3%.
Operating income at mission systems rose 12%, and operating margin rate increased to 15.3%.
Space systems operating income increased 37%, primarily due to higher sales volume.
Operating margin rate rose to 10.9% due to higher net favorable EAC adjustments, driven by the reduction in overhead rates.
At the total company level, segment operating income increased 13% in Q1, and operating margin rate increased to 12%.
As a result of a continued robust growth in our space business and the recent win of the NGI program, we are increasing space sales guidance to approximately $10 billion.
We now expect 2021 sales will range between 35.3 and $35.7 billion, a 200 million increase to prior guidance.
Keep in mind that our fourth quarter year-over-year revenue comparison will include headwinds of fewer working days and the $444 million equipment sale at AS in addition to the divestiture.
We are increasing our transaction adjusted earnings per share to a range of $24 to $24.50 from our prior guidance range of $23.15 to $23.65.
As Kathy mentioned, first-quarter operating cash flow increased more than $900 million from Q1 2020.
It's worth mentioning that while the divestiture of the IT services business closed in Q1, federal and state cash taxes of approximately $800 million will be paid over the remainder of the year.

Summary:
We booked new awards of $8.9 billion, grew sales 6% and increased segment operating income, 13%.
GAAP earnings per share of $13.43 reflects the IT services gain and transaction-adjusted earnings per share increased 28% in the quarter.
We reported Q1 sales growth of approximately 6%.
GAAP earnings per share increased to $13.43, primarily due to the gain on sale.
When we adjust for the divestiture-related items, transaction adjusted earnings per share are up 28% to $6.57.
Aeronautics systems sales were up 5% for the quarter, reflecting higher Manned Aircraft sales due to stronger volume on restricted programs and E-2D, partially offset by lower sales in autonomous systems as certain Global Hawk production programs near completion.
Sales were higher in both business areas, with continued ramp-up on the GBSD program, driving revenue growth in launch and strategic missiles.
We now expect 2021 sales will range between 35.3 and $35.7 billion, a 200 million increase to prior guidance.